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Arthritis mutilans is the most severe form of psoriatic arthritis (PsA). Fewer than 5 percent of people with PsA develop this rare disorder. It causes deformities and dysfunction primarily in the small joints of the fingers and toes, according to the National Psoriasis Foundation (NPF). In rare cases, arthritis mutilans can also occur in people with rheumatoid arthritis.
Bone loss (osteolysis) is a key feature of arthritis mutilans, in addition to stiff joints, decreased range of motion, and other PsA symptoms. Osteolysis causes a dramatic deformity of hand and foot digits — also known as “opera-glass finger” or “telescoping finger” — making it hard to straighten or bend a joint.
Early diagnosis and treatment of arthritis mutilans is critical to limit or stop disease progression, which can permanently damage or destroy the joints. A delay of more than six months from the time of first symptoms to a visit with a rheumatologist can worsen long-term outcome.
Of the five forms of psoriatic arthritis, arthritis mutilans is the most aggressive and advanced type. Although the cause is not known, arthritis mutilans typically occurs when the immune system mistakenly attacks healthy cells in joints. The resulting inflammation causes bone tissue to break down and become reabsorbed into the body.
People with PsA who are not currently in treatment — or whose condition has been unresponsive to treatment — are at the highest risk of developing arthritis mutilans. Having a family history of psoriasis or PsA are also risk factors. About 40 percent of people with PsA, for example, have a family member with psoriasis or arthritis, suggesting a genetic link.
Unlike rheumatoid arthritis, which affects both sides of the body, arthritis mutilans usually appears in an asymmetric pattern on one side of the body. It typically affects the small bones of the hands and feet, specifically the distal interphalangeal joint (at the end of the fingers), metacarpophalangeal (knuckle) joint in the hands, and metatarsophalangeal joints in the feet. Classic symptoms of arthritis mutilans include telescoping fingers and pencil-in-cup deformity.
Sometimes referred to as opera glass hands (or feet), this symptom occurs when connective tissues can’t support the joints in fingers and toes, causing them to shorten or bunch together. Pulling on fingers may cause them to lengthen or open up like opera glasses. The joints may flail in unusual directions. Collapsed digits can also create excess skin that appears folded like a telescope.
Severe joint erosion typical of arthritis mutilans causes pencil-in-cup deformity. The end of a bone in a finger or toe narrows like a pencil point, while the top of the neighboring bone is eroded into a cup-like shape. This damage is typically seen with an X-ray.
Other symptoms of arthritis mutilans include:
A 2015 systematic review of current literature on arthritis mutilans found that it is a polyarthritis disease; the majority of people who developed it had multiple affected joints. In a 2017 Scandinavian study of 67 people with arthritis mutilans, the average number of damaged joints per person was 8.2.
Although it is rare that psoriatic arthritis becomes arthritis mutilans, the condition can progress rapidly from PsA. Arthritis mutilans could occur within a few months or up to several years after the onset of PsA.
Less commonly, arthritis mutilans has been associated with axial spondyloarthritis — a chronic, inflammatory disease of the spine and sacroiliac joints (that can lead to sacroiliitis where the lower spine meets the pelvis). While not a classic arthritis mutilans symptom, sacroiliitis is present in many people with arthritis mutilans.
Because psoriatic arthritis mutilans and rheumatoid arthritis have similar symptoms, a diagnosis can be mistaken or delayed. Diagnosis is typically based on a family history of psoriasis, genetic markers, and the presence of such PsA symptoms as dactylitis (“sausage” fingers or toes) and enthesitis (inflammation of tendons and ligaments that attach to bone).
A rheumatologist will first perform a physical exam to confirm the type of arthritis, checking joints for swelling or tenderness. A blood test can detect certain antibodies or rheumatoid factor (RF) whose presence would indicate rheumatoid arthritis. Diagnosis also involves radiographic imaging (X-rays) to investigate the type and degree of bone loss.
Currently, there are no medicines specifically approved for treating arthritis mutilans. It’s still important to seek treatment as early as possible, as there are many options for managing symptoms and slowing disease progression. Depending on the severity of the disease and joint destruction, rheumatologists may prescribe one or more of the following treatments commonly used for people with psoriatic arthritis.
Guidelines developed by the National Psoriasis Foundation and the American College of Rheumatology currently recommend biologic drugs as the first-line treatment for severe PsA. Biologics are either injected or given in an intravenous infusion (by IV). They’re usually taken long-term as maintenance drugs to prevent disease flares and progression. Biologics can reduce inflammation and protect joints, but they don't reverse damage and deformity.
Tumor necrosis factor inhibitors, one class of biologics, are treatments for severe PsA that hasn’t responded to other therapies. TNF inhibitors are often highly effective at treating a wide range of PsA symptoms, including those in arthritis mutilans.
Newer biologics approved for psoriatic arthritis, including arthritis mutilans, stop inflammation by inhibiting certain functions in the body. They include Stelara (Ustekinumab), Cosentyx (Secukinumab), and Taltz (Ixekinumab).
Disease-modifying antirheumatic drugs (DMARDs) are systemic drugs prescribed for moderate to severe PsA, including arthritis mutilans. They can impact the disease course by reducing joint and tissue damage, slowing disease progression, and relieving symptoms.
Read Treatments for Psoriatic Arthritis for more about specific biologic DMARDs, including side effects.
Nonsteroidal anti-inflammatory drugs (NSAIDs) are typically used to manage symptoms of psoriatic arthritis, including arthritis mutilans. NSAIDs can reduce swelling and pain, making it easier to walk and move, but they don’t limit disease progression or joint damage. Popular over-the-counter NSAIDs for arthritis mutilans include aspirin, Advil or Motrin (Ibuprofen), and Aleve (Naproxen). Long-term use of NSAIDs can cause side effects, including stomach problems such gastrointestinal bleeding and ulcers.
Also known as steroids, corticosteroids may be injected into joints to reduce ongoing inflammation in people with arthritis mutilans. Injections allow doctors to deliver a higher medication dose than is possible with oral medications.
Long-term use of steroids can increase joint damage, as well as the risk of infection, bone fractures, and chronic diseases such as osteoporosis, high blood pressure, obesity, diabetes, and heart disease.
To help delay the progression of arthritis mutilans, rheumatologists recommend early and aggressive physical and occupational therapy. Hand therapy is particularly important because it strengthens muscles around the joints, improving dexterity and overall use of fingers and hands.
Joint replacement surgery, bone grafts, or joint fusion (arthrodesis) may be an option for severely damaged joints. These procedures can help relieve symptoms, restore some function, and improve quality of life with arthritis mutilans. Surgery should be considered a last resort because it typically requires downtime for recovery, and there are risks of infection.
Arthritis mutilans can have a significant impact on quality of life. In a 2017 Scandinavian study of people with arthritis mutilans, 42 percent retired early or took sick leave, while 21 percent could not care for themselves on a daily basis.
With good self-care, however, it’s possible to reduce symptoms, improve functioning in hands and feet, and boost overall health and well-being. Adopting a balanced, anti-inflammatory diet, maintaining a healthy weight, engaging in gentle exercise, and quitting smoking can help put the brakes on inflammation and make you more responsive to treatment.
Complementary therapies, such as meditation, acupuncture, and stress management techniques, have helped some people better manage the pain and symptoms of psoriatic disease, including arthritis mutilans.